Air pump cycles on and off when car not running 2000 passat

Improper fuel/air mixture, possibly plugged up air filter?
You have 2 out of 3 of the needed components for that motor to run, and assuming your timing is correct and you have compression, it could be an air intake issue.

fuel pressure

It's very likely that you need to replace the fuel pump. Usually, if its that loud either its sucking air (because you're out of gas) or the pump is about to go out.

The serpentine belt routing diagram on a 2000 VW Passat 1.9 TDI - 90 HP


CS = Crankshaft
F = Fan pulley
Gen = Alternator
T = Tensioner
AC = Air Conditioning
PAS = Power Assisted Steering
WP = Water Pump

it could be the thermostat. if the car stays at normal operating temp at idle and only gets hot when you drive it is the water pump. i just changed one that never overheated at idle even when it set for an hour or more. as soon as I tried to drive it I would get a mile down the road and it would be burning hot. took the water pump off and the impeller was spinning on the pump shaft.

You don't really need the air pumps at all, if you can pass DEQ without it, so try it first. All they do is make the catalytic converter hotter, and shift more harmless soot to toxins they don't measure.

Does temp gauge on dash show normal temp? If so problem is with the controls. If sytem cycles through normal controls IE, defroster, floor,bi-level and redirects air properly check to make sure door control is functional for heater core. If door is not opening then you will never get hot air

i have 2 keys for my passat.with 1 key the engine runs perfect and with the other key the engine runs 2-3 seconds

I have a 2000 Passat (1.8T), and I recently had this code (P0411). First thing I did was to clean the mass airflow sensor (MAF) and reset the code by disconnecting the battery. Unfortunately, the code came back. It also came back with P1426. It ended up being the purge valve ($60 at ECSTuning, $140 at the dealer...I went with ECSTuning). Before you drop money on the part, inspect all of the hoses to ensure they are not cracked or torn.

please rate me solved...thanks

DTC P0411/16795: SECONDARY AIR SYSTEM - INCORRECT FLOW DETECTED
Test Requirements
Ensure all fuses are okay, battery voltage is at least 11.5 volts, all electrical accessories are off, A/C is off.
Ensure engine is mechanically sound.
Test Procedure

NOTE
Secondary air system is activated by ECM and blows air into exhaust pipe
upstream of catalytic converter for 100 seconds during a cold start, 41-91°F (5-
33°C). Engine must be cold to perform following test procedure.

1. Ensure fuse and secondary fuse (secondary fuse is 40 amp and is located in fuse holder on top of battery)
are okay. Check hoses and components of Secondary Air Injection System, for damage, loose fit and
improper installation, check vacuum hoses for Secondary Air Injection System. Repair as necessary.
Erase DTC memory. Verify repair. If DTC does not reset, test is complete. Perform ECM relearn
procedure. See TEST DRIVE RELEARN PROCEDURE .
2. Remove engine cover. Disconnect pressure hose from Secondary Air Pump Motor (V101), by pressing
buttons on hose connector. See Fig. 33 . Using scan tool, check Secondary Air Pump Motor (V101) in
scan tool Output Diagnostic Test Mode (Secondary Air Pump Relay activation mode). See OUTPUT
DIAGNOSTIC TEST MODE .
3. Secondary Air Pump Motor (V101) should run in intervals and air should exit pump at hose connection.
If Secondary Air Pump Motor (V101) is okay, go to step 7 . If motor runs and no air exits secondary air
pump motor, replace faulty Secondary Air Pump Motor (V101). Erase DTC memory. Verify repair. Test
is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE . If
secondary air pump motor does not run, go to next step.
4. Disconnect Secondary Air Pump Motor (V101) harness connector, install LED test light at secondary air
pump harness connector terminals. Turn ignition on. Using scan tool, activate Secondary Air Pump Motor
(V101) in scan tool Output Diagnostic Test Mode (Secondary Air Pump Relay activation mode). See
OUTPUT DIAGNOSTIC TEST MODE . LED test light at Secondary Air Pump Motor (V101) harness
connector should flash. If LED test light at Secondary Air Pump Motor (V101) harness connector does
not flash, go to next step. If LED test light at Secondary Air Pump Motor (V101) harness connector
flashes, replace faulty Secondary Air Pump Motor (V101). Erase DTC memory. Verify repair. Test is
complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .
5. Using DVOM check resistance of Secondary Air Pump Motor (V101) wiring. See appropriate WIRING
DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. Resistance should
be a maximum of 1.5 ohms for each reading. Check wiring for short circuit to one another in Secondary
Air Pump Motor (N101) harness connector. Repair as necessary. Erase DTC memory. Verify repair. Test
is complete. Perform ECM relearn procedure.
Secondary Air Pump Motor (N101) wiring is okay, go to next step.
6. Check Secondary Air Pump Relay (J299) and Secondary Air Pump Relay (J299) wiring. See DTC
P0418/16802: SECONDARY AIR PUMP RELAY (J299), MALFUNCTION . Repair or replace as
necessary. Erase DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See
TEST DRIVE RELEARN PROCEDURE .
7. Disconnect vacuum hose from Secondary Air Injection Valve (N112) and disconnect pressure hose from
secondary air pump motor, press buttons on pressure hose connector to disconnect pressure hose. See Fig.
34 . Blow lightly into disconnected pressure hose, Combi-Valve should be closed. Connect hand vacuum
pump to disconnected vacuum hose and apply vacuum to Combi-Valve, Combi-Valve should open. If
Combi-Valve opens when vacuum is applied, Combi-Valve is okay. Go to next step. If Combi-Valve
does not open when vacuum is applied, replace faulty Combi-Valve. Erase DTC memory. Verify repair.
Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .
8. Check Secondary Air Injection Valve (N112). See DTC P0412/16796: SECONDARY AIR
INJECTION VALVE (N112), ELECTRICAL CIRCUIT MALFUNCTION . Repair as necessary.
Erase DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure.
NOTE: Do not use compressed air to check Combi-Valve.
2000 Volkswagen Passat GLS
2000 ENGINE PERFORMANCE Self-Diagnostics - 1.8L Turbo